1. Field
The present disclosure relates to a centrifugal fan.
2. Background
A centrifugal fan is a fan for accelerating air axially introduced through a shroud to discharge the air through gaps between blades in a radial direction (or in a centrifugal direction). The performance of the centrifugal fan is influenced by various form factors besides fiction and shock losses. For example, the typical factors affecting the performance of the centrifugal fan include a rotational speed, a shape of a blade, main plate, or shroud, and the number or angles of blades.
In the centrifugal fan, after air is introduced through an inlet port formed at a central portion of the shroud and is accelerated by the blades, the air is discharged along an outer periphery of the shroud in an upper region near to the inlet port while being discharged along an outer periphery of the main plate in a lower region far from the inlet port. In this case, eddies are generated due to flow separation generated in the respective outer peripheries of the shroud and main plate in the related art, resulting in poor efficiency of the fan and noise generation.
In particular, since air introduced through the shroud is pressurized by the blades in the course of reaching the main plate in a direction of an axis of rotation and is then discharged, a difference in flow velocity is generated between the upper and lower regions. For this reason, the air is not uniformly discharged across the upper and lower regions. Particularly, there is a problem in that the fan has poor efficiency and noise increases due to eddies generated by the difference in flow velocity between the upper and lower regions.